/*

     File: ProgressObserver.h

 Abstract: 

    This model class uses Key Value Observeration (KVO) to monitor the NSProgress for Multipeer Connectivity API resource sending/receiving completion progress (or cancellation). 

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*/

@protocol ProgressObserverDelegate;

// This class is a helper class which implements KVO on the NSProgress cancel and completedUnitCount properties.

// This is useful for driving a UIProgressBar for exmaple

@interface ProgressObserver : NSObject

// Human readable name string for this observer

@property (nonatomic, readonly) NSString *name;

// NSProgress this class is monitoring

@property (nonatomic, readonly) NSProgress *progress;

// Delegate for receiving change events

@property (nonatomic, weak) id<ProgressObserverDelegate> delegate;

// Designated initializer

- (id)initWithName:(NSString *)name progress:(NSProgress *)progress;

@end

// Protocol for notifying listeners of changes to the NSProgress we are observing

@protocol ProgressObserverDelegate <NSObject>

// Called when there is a change to the completion % of the resource transfer

- (void)observerDidChange:(ProgressObserver *)observer;

// Called when cancel is called on the NSProgress

- (void)observerDidCancel:(ProgressObserver *)observer;

// Called when the resource transfer is complete

- (void)observerDidComplete:(ProgressObserver *)observer;

@end